1. Field of the Invention
The present invention is concerned with a precision phase shift system which provides precise control over successive phase-shifting steps of output signals and which allows precise matching with corresponding object signals for subsequent decoding thereof.
2. Description of the Prior Art
In the decoding of signals such as those received from a global position satellite, it is necessary to synchronize with the incoming signals. In order to do this, the internally generated signals must match both the frequency and phase of the incoming signals. In the prior art, matching the phase of the internal and received signals has presented the greatest difficulty.
For example, the prior art discloses a synchronous counter which phase shifts a signal over an entire period by performing many counter increments. To gain acceptable precision, the counter and associated components must have sufficient capacity to step through the many required steps. This results in a large number of components which increases the complexity, size and cost of the circuitry.
Variable modulus counters which are often used in frequency generators are also sometimes used for phase shifting. These types of counters, however, present the same disadvantages of complexity, size and cost. Accordingly, the prior art points out the need for a system which allows very precise phase shifting of a signal while minimizing the number of components, size, and manufacturing cost.